Removable drill pipe protector



R. C. BAKER REMOVABLE DRILL PIPE PROTECTOR July 28, 1959 Filed Sept. 26. 1955 2 Sheets-Sheet 1 M a L w v w v MM 7% 7 1i a k 2 n 5 3 a INVENTOR." Jazz/3: C. 34422 y 1959 R. c. BAKER REMOVABLE DRILL PIPE PROTECTOR Filed Sept. 26. 1955 2 Sheets-Sheet 2 y R m a e m a W a M 3 M. 5 w [w M United States Patent REMOVABLE DRILL PIPE PROTECTOR Reuben C. Baker, Coalinga, Califi, assignor to Baker 'Oil Tools, Inc, Los Angeles, Calif., a corporation of California Application September 26, 1955, Serial No. 536,570

1 Claim. (Cl. 308-4) The present invention relates to protective devices adapted to be mounted on drill pipe, and the like, for use during the rotary drilling of oil, gas, water, and similar well bores.

An object of the invention is to provide an improved drill pipe protector that can be, readily mounted on and removed from a drill pipe section.

Another object of the invention is to provide a drill pipe protector capable of being moved laterally of the drill pipe in mounting it on or demounting it from the pipe, the protector tenaciously gripping the drill pipe to resist its movement on the pipe under the conditions encountered in the Well bore.

A further object of the invention is to provide a drill pipe protector movable laterally of the drill pipe in being mounted thereon or removed therefrom, which is of strong and strudy construction, and economical to manufacture.

Yet another object of the invention is to provide a rubber or rubber-like drill pipe protector longitudinally split at one side to enable the protector to be moved laterally onto a drill pipe, in which substantially no gaps remain at the split portion of the protector after it has been mounted on the pipe.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claim.

Referring to the drawings:

Fig. 1 is an isometric projection, partly in section, of a drill pipe protector mounted on drill pipe disposed in a well bore;

Fig. :2 is a top plan view of the protector;

Fig. 3 is an isometric projection of the reinforcing sleeve, which is molded within the rubber body of the protector;

Fig. 4 is a side elevation of the protector;

Fig. 5 is a longitudinal section taken generally along the line 5-5 on Fig. 2;

Fig. 6 is an isometric view of a portion of the reinforcing sleeve.

The protector A disclosed in the drawings is adapted to be mounted on drill pipe B used in the rotary drilling of an oil, or similar well by moving it laterally of the drill pipe. It can also be demounted from the latter by a lateral movement with respect to the drill pipe.

The protective device itself includes an annular body 10 of rubber, in which a reinforcing sleeve 11 is molded. The annular body of rubber has a longitudinal split 12 at one side, while they reinforcing sleeve is of a sectional,

hinged construction, so as to enable the protector A to v ice be opened at its split side for lateral insertion on the drill pipe B and removal therefrom.

The reinforcing sleeve 11, itself, is made of two like sections 13, which are preferably formed from sheet metal. Each section has a longitudinal extent slightly less than the length of the rubber body portion 10 of the protector. It consists of an inner ply 14 of circular or arcuate form merging into hinge knuckles 15, 16 at its opposite ends. The hinge knuckles 16 at one end are integral with an outer ply 17 lying snugly against the inner ply 14, extending partly around its periphery. The hinge knuckles 15 at the opposite end of the sleeve merge into another outer ply 18 that extends toward the other outer portion 17 of the reinforcing sleeve, lying snugly against the periphery of the inner ply 14. This outer portion 18 has an ofiset marginal portion 19 spaced outwardly from the inner ply 14 to form a groove or recess 20 for receiving the marginal end 21 of the other outer portion 17.

The various plys and portions are rigidly and permanently secured to each other, as by use of a plurality of spot welds 22 at appropriately spaced portions along their contacting areas. It is apparent that each section 13 of the sleeve 11 is made of a single piece of she-st metal, having longitudinally spaced hinge knuckles 15, 16 at its end portions, the hinge knuckles 15 at one end of the section being in staggered relation .with respect to the hinge knuckles 16 at the other end of the section.

Two like sections 13 may be assembled to each other, the hinge knuckles 15 of one section interleaving with respect to the hinge knuckles 16 of the other section, to permit a hinge pin 23 to be inserted through such knuckles and thereby pivotally secure the section together at one side. A suitable lock pin 24 can be inserted through the interleaved and aligned hinge knuckles 15, 16 at the opposite side of the sections 13, to secure these particular sections together. The lock pin 24 is preferably removable, but the first-mentioned hinge pin 23 may be inserted through the knuckles 15, 16 at one side of the sleeve 11 and remain in place.

The sections 13 of the sleeve, when assembled together, form a composite generally cylindrical structure having a diameter that is substantially greater than the outside diameter of the drill pipe B on which the protector A is to be mounted. The maximum outside diameter of the sleeve is substantially less than the outside diameter of the rubber body portion 10 of the protector. The inside diameter of the sleeve is substantially greater than the inside diameter of the body portion 10 of the protector. The arrangement is such that a cylindrical surface lying substantially centrally of the sleeve 11 passes through the axes of the sets of interleaved knuckles 15, 16 and of the hinge pin 23 and lock pin 24 passing therethrough. The reinforcing and operating sleeve 11 is provided with a plurality of openings or windows 25 therethrough, through which the rubber or rubber-like protector body 10 can pass or flow during the molding operation, as described hereinbelow.

The protective sleeve 11 is molded within the rubber body 10 of the protector itself. The hinge pin 23 at one side of the sleeve sections 13 is disposed in place and the composite reinforcing sleeve 11 placed in a suitable mold (not shown). An appropriate mandrel (not shown) is inserted within the sleeve 11, to support the sleeve within the mold. The mandrel has longitudinally spaced members that will engagethe sleeve structure 11 at space locations around its interior.

Suitable pins (notshown) are inserted through the hinge knuckles 15, 16 at the side of the sleeve structure opposite the side in which the hinge pin 23 has been inserted, in such manner as to holdthe sleeve in'a slightly 3 open'position with the hinge knuckles 15, 16 slightly disaligned with respect to each other. The inner mandrel (not shown) will be appropriately shaped so that a plurality of circumferential internal ribs 26 are provided in the rubber protector body, these ribs having a purpose that will be described hereinbelow. A suitable longitudinal shim (not shown) will also be included in the mold to form the longitudinally extending split 12 at one side of the protector body at the region of the hinge knuckles 15, 16 that are to reecive the lock pin 24.

Anappropriate quantity of rubber or rubber-like material is forced into the mold and around the mandrel, the rubber material completely covering the hinge knuckles 15, 16 and the hinge pin 23 at one side of the protector, which remains permanently disposed within these hinge knuckles. The rubber packing material will also extend above and below the knuckles and pin 23 to the desired extent. Suitable thickness of rubber body material will also be disposed inwardly of the inner surfaces of the sleeve sections 13 and its hinge knuckles 15, 16, the ribs 26 projecting inwardly from such thickness of material. Recesses 27 are also formed during the molding operation in the rubber body material 10 above and below the uppermost and lowermost hinge knuckles 15, 16 respectively, at the side of the protective sleeve opposite the hinge pin 23, to permit the insertion and removal of the lock pin 24 in assembling and demounting the protective device on the drill pipe B.

After the molding operation has been completed, the protective device A, with the reinforcing sleeve 11 and the hinge pin 23 embedded in the rubber body It), is removed from the mold. The shim that. forms the longitudinal split 12 in the rubber body material is also removed, as well as the pins, or other devices, that held the interleaved hinge knuckles 15, 16 opposite from the pin 23 out of alignment with respect to each other. The extent of disalignment between these knuckles is selected so that, when aligned, the opposed faces 28, 29 of the rubber body 10 at the split 12 will abut one another, leaving no gaps along the length of the rubber body, except at its upper and lower ends.

The longitudinally spaced circumferential ribs 26 within the rubber body are generally V-shaped in cross-section. The upper half of the ribs 26 may face in an upward direction, whereas the lower half of the ribs may face in a downward direction. Each rib 26 is of generally triangle cross-section, with the base 30 of the triangle substantially normal to the axis of the protector, and with the inclined surface 31 of the rib facing either in an upward or a downward direction, as shown; Longitudinally spaced circumferential grooves 32 are formed in the body 10, that are deeper than the spaces 33 between adjacent rubber ribs 26, by the portions of the mandrel apparatus used in the molding operation, which extend inwardly to the reinforcing sleeve 11 to support the latter appropriately within the mold. To insure the proper flowing of the rubber material during the molding operation to all parts of the mold, the mandrel elements supporting the sleeve are preferably cut away at circumferentially spaced points which will result in the provision of rubber material extending inwardly of the groove at such spaced points 34 in the finished rubber body.

When the protector is in closed position but not mounted on a section of drill pipe B, the internal diameter of each rib 26 is less than the external diameter of the drill pipe on which the protector is to be mounted. Accordingly, when the protector is appropriately mounted on the drill pipe, the ribs 26 will be compressed against the periphery of the pipe B, the ribs being capable of displacement in a longitudinal direction into-circumferential groove portions 33 defined between adjacent ribs.

The upper and lower corner portions 35 of the protector body are preferably tapered, in order that the hanging up of the protector in casing coupling spaces, or on minor obstructions in the well bore, will be prevented.

In assembling the protector A on a drill pipe B, it is expanded about the axis of the hinge pin 23 to spread the protector at its split side apart sufficiently, enabling it to be moved laterally or sidewise over the pipe B, whereupon the split faces 28, 29 of the protector are moved toward each other to place the hinge knuckles 15, 16 in interleaved relation withrespect to each other. An appropriate contracting tool (not shown) placed around the rubber protector might be necessary in securing the assembly of the protector on the drill pipe section. This tool is appropriately manipulated to contract the protector until the hinge knuckles 15, 16 are in alignment with each other, whereupon a suitable lock pin 24, such as a cotter pin, is passed through the'interleaved hinge knuckles, the head 36 of the cotter pin being disposed in one of the recesses 27 of the body 10 of the protector, and the opposed legs 37 of the cotter pin within the other recess 27 then being spread apart sufiiciently to prevent inadvertent removal of the cotter pin. When the cotter pin 24 has been placed through the hinge knuckles 15, 16, the opposed faces 28, 29 of the rubber body 10 on opposite sides of the split 12 will abut each other, and such abutting relation will occur throughout the entire longitudinal extent of the rubber body 10, except for the recesses 27 at the upper and lower ends of the latter, which, it will be noted, are disposed in the inclined end portions 35 of the rubber body material, and hence in a location that will not bear against surface casing C or any other surrounding object in which the protector is operating.

In fully closing the protector around the drill pipe to place the hinge knuckles 15, 16 in alignment with each other, the longitudinally spaced circumferential ribs 26 will be compressed against the exterior of the drill pipe B, tenaciously gripping the latter and preventing'relative movement of the protector on the drill pipe section during the drilling operation in the well bore.

The drill pipe may now be rotated and used in its normal manner to drill the hole, the protector A preventing the drill pipe B from bearing against the surface casing C in which the protector is located. Upon the removal of the drill pipe from the well bore, the protector can easily be disassembled from the drill pipe section. It is merely necessary to bend the ends 37 of the cotter pin 24 back toward each other and to remove the cotter pin from the hinge knuckles 15, 16, whereupon the protector A can spread sufficiently at its split portion 12 for sidewise or lateral movement from the drill pipe.

If assembly of the protector on the drill pipe is again desired, it is merely necessary to spread the protector apart at its split region 12 sufficiently to move it laterally back onto the drill pipe, whereupon the protector is fully contracted around the latter with its ribs 26 pressed thereagainst, and the cotter pin 24, or similar lock pin, reinsertedwithin the hinge knuckles 15, 16. I

The protector described is relatively easily to mount on drill pipe and to remove therefrom. It is of an exceedingly strong and sturdy construction, in View of the reinforcing sleeve 11, which is molded within the rubber body material itself. This sleeve is economical to manufacture, since it is made from two pieces of sheet metal. Its hinge construction facilitates the opening and closing of the protector for the purpose of moving it laterally with respect to the drill pipe. The lock pin 24 and hinge knuckles 15, 16 arrangement extends along substantially the entire length of the protector at its split portion 12, and, therefore, provides a very strong holding device for maintaining the protector in its locked position on the drill pipe, with the inner surface of the protector body 10 firmly gripping the periphery of the drill pipe. The alignment of the hinge knuckles 15, 16 at the lock side of the protector places the opposed faces 28, 29 of the rubber body material in abutting relation to each other, preventing any gap between the opposed faces that might result in the tearing of the rubber body material during use of the protector.

The inventor claims:

In a drill pipe protector: an annular collar member of pliant, elastic material split substantially longitudinally at one side thereof and having longitudinally extending contactable opposed faces on opposite sides of said split; a generally cylindrical sleeve embedded in said member between its inner and outer walls and extending circumferentially therearound; said sleeve comprising sections having interleaved hinged knuckles remote from said split lying inwardly of the outer wall of said member and spaced outwardly of the inner wall of said member so that said knuckles are substantially centered in said member radially thereof with a substantial thickness of said material disposed between said knuckles and each of said walls; a hinge pin passing through said knuckles; said sections having lock knuckles on opposite sides of said split lying inwardly of the outer wall of said member and spaced outwardly of the inner wall of said member so that said lock knuckles are substantially centered in said member radially thereof with a substantial thickness of said material disposed between said lock knuckles and each of said walls; said lock knuckles being adapted to interleave with each other; said opposed faces abutting one another when said lock knuckles on opposite sides of said split are aligned; lock means extending through said interleaved and aligned lock knuckles to hold said sleeve and member in contracted position with said faces abutted against each other; a cylindrical surface conforming to and substantially central of said sleeve passing through the axes of said interleaved hinge knuckles and lock knuckles; each section comprising an inner ply integral with and merging at its opposite ends into said hinge knuckles and lock knuckles, a first outer ply integral with and extending from said hinge knuckles along the exterior of said inner ply, a second outer ply intgeral with and extending from said lock knuckles along the exterior of said inner ply, said outer plies overlapping each other, and means securing said plies together.

References Cited in the file of this patent UNITED STATES PATENTS 2,002,893 Holt et al May 28, 1935 2,197,531 Smith Apr. 16, 1940 2,251,428 Smith Aug. 5, 1941 2,606,792 Marsh Aug. 12, 1952 FOREIGN PATENTS 611,887 Great Britain Nov. 4, 1948 

